Partial Solar Eclipse of November 25

The fourth and final solar eclipse of the year occurs at the Moon's ascending node in western Scorpius. The event is visible from high latitudes in the Southern Hemisphere and includes southern South Africa, Antarctica, Tasmania and most of New Zealand (Figure 5).

At the instant of greatest eclipse (06:20:17 UT) the eclipse magnitude is 0.905, making it the largest partial eclipse of the year. At that time, the lunar shadow axis will pass just 330 km above Earth's surface near the coast of Antarctica.

This is the 53rd eclipse of Saros 123. The family began with 6 partial eclipses from the years 1074 to 1164. By the time the series ends in 2318, it will have produced 70 eclipses in the following order: 6 partial, 27 annular, 3 hybrid, 14 total, and 20 partial eclipses. Complete details for Saros 123 can be found at:

Total Lunar Eclipse of December 10

The last eclipse of 2011 is a total lunar eclipse that takes place at the Moon's descending node in eastern Taurus, four days after apogee.

The Moon's orbital trajectory takes it through the southern half of Earth's umbral shadow. Although the eclipse is not central, the total phase still lasts 51 minutes. The Moon's path through Earth's shadows as well as a map illustrating worldwide visibility of the event are shown in Figure 6. The timings of the major eclipse phases are listed below.

Penumbral Eclipse Begins: 11:33:32 UT
Partial Eclipse Begins: 12:45:42 UT
Total Eclipse Begins: 14:06:16 UT
Greatest Eclipse: 14:31:49 UT
Total Eclipse Ends: 14:57:24 UT
Partial Eclipse Ends: 16:17:58 UT
Penumbral Eclipse Ends: 17:30:00 UT

At the instant of greatest eclipse (14:32 UT) the Moon lies at the zenith in the Pacific Ocean near Guam and the Northern Mariana Islands. The umbral eclipse magnitude peaks at 1.1061 as the Moon's centre passes 21.4 arc-minutes south of the shadow axis. The Moon's northern limb is then 6.4 arc-minutes south of the shadows axis and 33.3 arc-minutes from the umbra's edge. In contrast, the Moon's southern limb lays 36.5 arc-minutes from the shadow centre and 3.2 arc-minutes from the southern edge of the umbra. Thus, the northern half of the Moon will appear much darker than the southern half because it lies deeper in the umbra.

Since the Moon samples a large range of umbral depths during totality, its appearance will change dramatically with time. It is difficult to predict the brightness distribution in the umbra, so observers are encouraged to estimate the Danjon value at different times during totality (see Danjon Scale of Lunar Eclipse Brightness). Note that it may also be necessary to assign different Danjon values to different portions of the Moon (i.e., north vs. south).

During totality, the winter constellations are well placed for viewing so a number of bright stars can be used for magnitude comparisons. Aldebaran (mv = +0.87) is 9° to the southwest of the eclipsed Moon, while Betelgeuse (mv = +0.45) is 19° to the southeast, Pollux (mv = +1.16) is 37° east, and Capella (mv = +0.08) is 24° north.

The entire event is visible from Asia and Australia. For North Americans, the eclipse is in progress as the Moon sets with western observers favored by a larger fraction of the eclipse before moonset. Observers throughout Europe and Africa will miss the early eclipse phases because they occur before moonrise. None of the eclipse can be seen from South America or Antarctica. The NASA JavaScript Lunar Eclipse Explorer is an interactive web page that can quickly calculate the altitude of the Moon during each phase of the eclipse from any geographic location:

http://eclipse.gsfc.nasa.gov/JLEX/JLEX-index.html

Table 6 lists predicted umbral immersion and emersion times for 20 well-defined lunar craters. The timing of craters is useful in determining the atmospheric enlargement of Earth's shadow (see Crater Timings During Lunar Eclipses).

The December 10 total lunar eclipse is the 23rd member of Saros 135, a series of 71 eclipses occurring in the following order: 9 penumbral, 10 partial, 23 total, 7 partial, and 22 penumbral lunar eclipses. Complete details for Saros 135 can be found at:
Forthcoming Eclipses in 2012
• Annular Solar Eclipse in May 20, 2012
• Venus Transit June 5-6, 2012
• Total Solar Eclipse on November 13, 2012

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